How do I set up an odd angled hinge?
The door will rotate around it's origin, so first move it's origin to the hinged edge.


In edit mode select the hinge edge of the door.
Snap Cursor to selected - &#8679; ShiftS->Cursor To Selected.
In object mode, set origin to geometry. &#9096; Ctrl&#9095; Alt&#8679; ShiftC->Origin to 3D Cursor.


Focusing on the door by itself, animate it so that it rotates on it's hinged side.


Align the hinged side of the door to the global Z-Axis.
Keyframe the door rotating on the Z-Axis.


Then parent the door to the empty and move the empty so that the doors rotation aligns with the wall.


Clear the rotation of the empty.
Align the empty to the bottom corner of the door.
Parent the door to the empty.
Move the empty so that the door aligns with the wall.